Leonardo da Vinci's abundant drawings and notebooks record his keen and tireless observation of all aspects of the natural world. He probably drew this study from life and his anatomical understanding of the animal may have been aided by his dissections of bears. The sheet relates to a group of bear studies that Leonardo probably produced for his planned anatomical treatise, about which he wrote: “I will discourse of the hands of each animal to show in what way they vary, as in the bear which has the ligatures of the toes joined above the instep.” The faint outlines of a seated woman are visible beneath the drawing of the bear, indicating that Leonardo reused the sheet.